Many vehicles such as boats, campers, trains, and aircraft include kitchens, bathrooms, and other facilities that generate various forms of liquid waste. Environmental concerns and movement of the vehicles generally prohibit or prevent discharging the liquid waste directly to the environment during operation of the vehicles. As a result, the vehicles often include one or more holding tanks that collect and store the liquid waste for subsequent disposal.
The liquid waste may be stored in the holding tanks for hours, days, or longer, and during this time, the liquid waste generates a wide variety of bacteria and other pathogens that emit undesirable odors and create the potential to spread disease to the surrounding environment. As a result, each holding tank often includes an exhaust vent outside of the vehicle that directs undesirable odors and other contaminants away from passengers inside the vehicle. While effective at preventing or reducing the spread of odors or contaminants inside the vehicle, the exhaust vent nonetheless allows the odors and contaminants to spread to areas outside the vehicle. For example, undesirable odors are typically present in the immediate vicinity of the exhaust vent outside the vehicle. In addition, particulates and other contaminants entrained in the exhaust tends to collect in higher concentrations on surfaces near the exhaust vent, increasing the risk of disease to people in the vicinity of the exhaust vent.
Various attempts have been made to neutralize odors and/or airborne pathogens from holding tanks. For example, pressurized systems or pumps may be used to inject chemicals or perfumes into the holding tanks to react with the liquid waste, but the chemicals and perfumes generally produce hazardous waste that requires additional disposal efforts, and the pressurized systems or pumps can be costly additions that require additional maintenance. Furthermore, pipes and fittings installed in the interior of a waste holding tank can obstruct or retard the flow of body waste, toilet paper and other objects when draining said tank in violation of plumbing code. Therefore, the need exists for a more cost-effective system to treat bacterial, viral, and other contaminants generated in holding tanks in vehicles to reduce or eliminate undesirable odors and contaminants in the vicinity of the vehicle.